LGTM with few nits. 

Thanks,
Steve

On Sun, Nov 28, 2021 at 7:44 PM Yunfei Dong <yunfei.dong@mediatek.com> wrote:
Different platform may has different numbers of register bases. Gets the
numbers of register bases from DT (sizeof(u32) * 4 bytes for each)
Few nits.
s/platform/platforms/
s/has/have/

Btw, what is DT?
 
Reviewed-by: Tzung-Bi Shih<tzungbi@google.com>
Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
---
 .../platform/mtk-vcodec/mtk_vcodec_dec_drv.c  | 37 ++++++++++++++-----
 1 file changed, 28 insertions(+), 9 deletions(-)

diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c
index e6e6a8203eeb..59caf2163349 100644
--- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c
+++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c
@@ -78,6 +78,30 @@ static irqreturn_t mtk_vcodec_dec_irq_handler(int irq, void *priv)
        return IRQ_HANDLED;
 }

+static int mtk_vcodec_get_reg_bases(struct mtk_vcodec_dev *dev)
+{
I see that dev is already checked before entering into this function, but null check for dev would still be nice. 
 
+       struct platform_device *pdev = dev->plat_dev;
+       int reg_num, i;
+
+       /* Sizeof(u32) * 4 bytes for each register base. */
+       reg_num = of_property_count_elems_of_size(pdev->dev.of_node, "reg",
+               sizeof(u32) * 4);
+       if (reg_num <= 0 || reg_num > NUM_MAX_VDEC_REG_BASE) {
+               dev_err(&pdev->dev, "Invalid register property size: %d\n", reg_num);
+               return -EINVAL;
+       }
+
+       for (i = 0; i < reg_num; i++) {
+               dev->reg_base[i] = devm_platform_ioremap_resource(pdev, i);
+               if (IS_ERR(dev->reg_base[i]))
+                       return PTR_ERR(dev->reg_base[i]);
+
+               mtk_v4l2_debug(2, "reg[%d] base=%p", i, dev->reg_base[i]);
+       }
+
+       return 0;
+}
+
 static int fops_vcodec_open(struct file *file)
 {
        struct mtk_vcodec_dev *dev = video_drvdata(file);
@@ -206,7 +230,7 @@ static int mtk_vcodec_probe(struct platform_device *pdev)
        struct resource *res;
        phandle rproc_phandle;
        enum mtk_vcodec_fw_type fw_type;
-       int i, ret;
+       int ret;

        dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
        if (!dev)
@@ -238,14 +262,9 @@ static int mtk_vcodec_probe(struct platform_device *pdev)
                goto err_dec_pm;
        }

-       for (i = 0; i < NUM_MAX_VDEC_REG_BASE; i++) {
-               dev->reg_base[i] = devm_platform_ioremap_resource(pdev, i);
-               if (IS_ERR((__force void *)dev->reg_base[i])) {
-                       ret = PTR_ERR((__force void *)dev->reg_base[i]);
-                       goto err_res;
-               }
-               mtk_v4l2_debug(2, "reg[%d] base=%p", i, dev->reg_base[i]);
-       }
+       ret = mtk_vcodec_get_reg_bases(dev);
+       if (ret)
+               goto err_res;

        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        if (res == NULL) {
--
2.25.1